
/**
 * Grid container
 */
#tiles {
list-style-type: none;
position: relative; /** Needed to ensure items are laid out relative to this container **/
margin: 0;
}

/**
 * Grid items
 */
#tiles li {
width: 612px;
background-color: #ffffff;
border: 1px solid #dedede;
/*-moz-border-radius: 2px;*/
-webkit-border-radius: 2px;
border-radius: 2px;
display: none; /** Hide items initially to avoid a flicker effect **/
cursor: pointer;
padding: 4px;
}

#tiles li img {
display: block;
}

/**
 * Grid item text
 */
#tiles li p {
color: #666;
font-size: 12px;
margin: 7px 0 0 7px;
}

/**
 * Some extra styles to randomize heights of grid items.
 */
#tiles ali:nth-child(3n) {
height: 175px;
}

#tiles ali:nth-child(4n-3) {
padding-bottom: 30px;
}

#tiles ali:nth-child(5n) {
height: 230px;
}

/** General page styling **/
  
html {
background-color: #e9e9e9;
}

#main {
padding: 30px 100px 30px 100px;/*此处可以修改主层次的相对位置*/
}

header h1 {
text-align: center;
font-size: 24px;
font-weight: normal;
margin: 30px 0 3px 0;
}

header p {
text-align: center;
font-size: 13px;
color: #777;
margin: 0;
}